The thermal degradation of poly(ditetrahydrofurfuryl itaconate)

Abstract

The goal of this investigation was to study the thermal degradation of poly(ditetrahydro-furfuryl itaconate) (PDTHFI) by thermogravimetry (TG). The monomer was polymerized in bulk at 40 degreesC using AIBN as initiator. Non-oxidative degradation was studied under nitrogen, while oxidative degradation was studied under air, applying four heating rates (2.5, 10, 20 and 40 K/min), up to 600 degreesC. The apparent activation energy of thermal degradation, E-a, was calculated using the Flynn-Wall method. The obtained non-oxidative TG curves of PDTHFI are parallel and no heating rate effect was observed. A carbonaceous residue remained at 600 degreesC, regardless of the heating rate applied. The E-a of PDTHFI is constant in the whole mass loss range and its mean value is 124 kJ/mol. The non-oxidative differential TG (DTG) curves of PDTHFI consist of two peaks, the second being dominant. If it is assumed that depolymerization is the main degradation mechanism, analogous to other polyitaconates, these two peaks could be ascribed to two depolymerization initiation modes: end-chain beta -scission and random main chain scission. The oxidative TG curves are more complex than the non-oxidative ones and show a heating rate effect. The E-a steadily increases in the mass loss range of 5-50% from 120 to 200 kJ/mol. The oxidative DTG curves consist of a major peak with two shoulders and a second minor peak.